It isn’t rare for departing chief executives to stick around for months or longer as chairman to help ease the transition to a new CEO in long planned successions. IBM’s Sam Palmisanodid that, for instance.

But it’s pretty rare for a CEO to remain on the board after leaving while under pressure to deliver faster change.

That arrangement can make things tough for an incoming CEO who has to fix problems while under the eye of a successor who let them develop in the first place. Ballmer’s initial decision to stay became an issue in the CEO hunt.

Ballmer’s departure gives new CEO Satya Nadella a freer hand to reshape the company. His term was to expire in the late fall. The former cited the burdens of his duties as new owner of the Los Angeles Clippers and other interests in stepping down early.